Preparation and laser powder bed fusion of composite microspheres consisting of poly(lactic acid) and nano-hydroxyapatite

Biocompatible and biodegradable poly(lactic acid) (PLA) and hydroxyapatite (HAP) are widely used for bone repair. In this study, microspheres consisting of poly(lactic acid) (PLA) and nano-hydroxyapatite (nano-HAP) were synthesized by emulsion solvent evaporation and were then used to fabricate layered parts using laser powder bed fusion (L-PBF). The effect of various parameters of the emulsion solvent evaporation technique on the size and morphology of the resulting PLA/nano-HAP microspheres was examined. We also evaluated how L-PBF parameters affected the physicochemical and biological properties of the fabricated parts. Nano-HAP was uniformly incorporated into PLA microspheres. Incorporation of HAP particles triggered pore formation on the microsphere surface. Layered parts fabricated by L-PBF using these composite microspheres as a material source showed good biocompatibility and osteogenesis. A 10 wt% of nano-HAP content in the layered part could effectively facilitate osteogenic differentiation of rat mesenchymal stem cells (rMSCs). Thus, L-PBF is a promising technology that can be used for manufacturing bone-repair implants consisting of PLA/nano-HAP composites materials.